1819961 has 18 divisors (see below), whose sum is σ = 2190510. Its totient is φ = 1510080.

The previous prime is 1819957. The next prime is 1819999. The reversal of 1819961 is 1699181.

It can be written as a sum of positive squares in 3 ways, for example, as 48400 + 1771561 = 220^2 + 1331^2 .

It is not a de Polignac number, because 1819961 - 2² = 1819957 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1819931) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 20405 + ... + 20493.

It is an arithmetic number, because the mean of its divisors is an integer number (121695).

2^1819961 is an apocalyptic number.

1819961 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1819961 is a deficient number, since it is larger than the sum of its proper divisors (370549).

1819961 is a wasteful number, since it uses less digits than its factorization.

1819961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137 (or 113 counting only the distinct ones).

The product of its digits is 3888, while the sum is 35.

The square root of 1819961 is about 1349.0593018841. The cubic root of 1819961 is about 122.0920428762.

The spelling of 1819961 in words is "one million, eight hundred nineteen thousand, nine hundred sixty-one".